| 摘要 |
PURPOSE:To improve the overall efficiency of an information recording/reproduction device by using a means which records the erasion permission information to a control information recording area of a recording medium and a means which erases the record information in response to the erasion permission information when no operating instruction is received for the recording/reproducing device. CONSTITUTION:A photomagnetic disk 10 is revolved at a fixed speed by a motor 11 via a controller 50 and a motor drive circuit 12. For a bias magnet 20, a bias magnet drive circuit 21 receives an indication form a controller 50. Thus the magnet 20 applies biases opposite to each other between the record and erasion modes and is turned off in a reproduction mode. An optical system 30 functions to maintain the light quantity for recording, reproduction and erasion respectively in response to an indication given from the controller 50. A timer 51 is incorporated to the controller 50 to perform each processing with indications given from an external device 70. If no indication is given for recording, reproduction and erasion during a period set by the timer 51, the controller 50 checks a memory to detect the presence or absence of the erasion permission information. Then the controller 50 erases the erasion permission information if detected and performs immediately the recording/reproducing job when an instruction is given from the device 70. |
